Browsing by Author "Orio, Marina"

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Broad Observational Perspectives Achieved by the Accreting White Dwarf Sciences in the Xmm-Newton and Chandra Eras
(Mdpi, 2025) Balman, Solen; Orio, Marina; Luna, Gerardo J. M.
Accreting white dwarf binaries (AWDs) comprise cataclysmic variables (CVs), symbiotics, AM CVns, and other related systems that host a primary white dwarf (WD) accreting from a main sequence or evolved companion star. AWDs are a product of close binary evolution; thus, they are important for understanding the evolution and population of X-ray binaries in the Milky Way and other galaxies. AWDs are essential for studying astrophysical plasmas under different conditions along with accretion physics and processes, transient events, matter ejection and outflows, compact binary evolution, mergers, angular momentum loss mechanisms, and nuclear processes leading to explosions. AWDs are also closely related to other objects in the late stages of stellar evolution, with other accreting objects in compact binaries, and even share common phenomena with young stellar objects, active galactic nuclei, quasars, and supernova remnants. As X-ray astronomy came to a climax with the start of the Chandra and XMM-Newton missions owing to their unprecedented instrumentation, new excellent imaging capabilities, good time resolution, and X-ray grating technologies allowed immense advancement in many aspects of astronomy and astrophysics. In this review, we lay out a panorama of developments on the study of AWDs that have been accomplished and have been made possible by these two observatories; we summarize the key observational achievements and the challenges ahead.
Citation - WoS: 14
Citation - Scopus: 13
The Remarkable Spin-Down and Ultrafast Outflows of the Highly Pulsed Supersoft Source of Nova Herculis 2021
(Iop Publishing Ltd, 2021) Drake, Jeremy J.; Ness, Jan-Uwe; Page, Kim L.; Luna, G. J. M.; Beardmore, Andrew P.; Orio, Marina; Osborne, Julian P.
Nova Her 2021 (V1674 Her), which erupted on 2021 June 12, reached naked-eye brightness and has been detected from radio to gamma-rays. An extremely fast optical decline of 2 magnitudes in 1.2 days and strong Ne lines imply a high-mass white dwarf. The optical pre-outburst detection of a 501.42 s oscillation suggests a magnetic white dwarf. This is the first time that an oscillation of this magnitude has been detected in a classical nova prior to outburst. We report X-ray outburst observations from Swift and Chandra that uniquely show (1) a very strong modulation of supersoft X-rays at a different period from reported optical periods, (2) strong pulse profile variations and the possible presence of period variations of the order of 0.1-0.3 s, and (3) rich grating spectra that vary with modulation phase and show P Cygni-type emission lines with two dominant blueshifted absorption components at similar to 3000 and 9000 km s(-1) indicating expansion velocities up to 11,000 km s(-1). X-ray oscillations most likely arise from inhomogeneous photospheric emission related to the magnetic field. Period differences between reported pre- and post-outburst optical observations, if not due to other period drift mechanisms, suggest a large ejected mass for such a fast nova, in the range 2 x 10(-5)-2 x 10(-4) M (circle dot). A difference between the period found in the Chandra data and a reported contemporaneous post-outburst optical period, as well as the presence of period drifts, could be due to weakly nonrigid photospheric rotation.